Programmable universal modem system and method for using the same

ABSTRACT

A system including a portable computer with a central processing unit and associated software, and a modem with an output jack carrying data transmit (TX), data receive (RX), tip, ring, and programmable digital input/output (DIO) lines sufficient to facilitate control of a large number of alternative telephone access devices. The operation and functions of the tip, ring, TX, RX and programmable DIO lines are controlled in a preferred embodiment by software in the modem under the control of the software in the computer. In a preferred embodiment, a user operates the software in the computer to specify a type or model of telephone access device being used with the modem, and the RX, TX, tip and ring lines are rendered either operable or inoperable, and a required subset of the programmable DIO lines are caused to operate in a manner necessary to achieve interactive control of an attached telephone access device.

This is a divisional application of Ser. No. 07/863,568, filed Apr. 6,1992, now U.S. Pat. No. 5,249,218.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a data transmission system and methodwhich can be selectively used with a landline telephone system or with avariety of alternative telephone systems, particularly radiotelephones.

2. Background Art

In years past, mobile data transmission was difficult in that there wasno public carrier capable of selectively connecting widely separatedmobile users wishing to exchange data. The first mobile informationtransmission systems of this type became widely available to the publicin the last decade, in the form of cellular radio telephone systems.These cellular telephone systems were primarily designed for voicecommunications, but inventors working in the field also developed datamodems for use with these cellular telephone systems. The firstcommercially practical modem of this type is disclosed in U.S. Pat. No.4,697,281 to O'Sullivan, assigned to the assignee of the presentapplication. This early modem was capable of sensing the characteristicsof a cellular bus, but the hardware of such modems was designedspecifically for a particular model of cellular telephone, so that thesame modem could not be used with a variety of different telephones.

One early attempt to solve this problem was the development ofmicroprocessor controlled interfaces which connected to a cellulartelephone bus and provided an external connector emulating a standardRJ-11 landline telephone jack. Some of these interfaces, such as theinterface disclosed in U.S. Pat. No. 4,718,080 to Serrano et al., werecapable of connecting to a plurality of cellular telephones andmodifying their operation to use each telephone effectively. The "AB-3X"sold by Morrison and Dempsey Communications, could function withdifferent cellular telephones if different connecting cables andinternal firmware chips were installed in the device. Other cellularinterfaces emulating a landline telephone jack are shown in U.S. Pat.Nos. 4,012,596, 4,658,096, 4,775,997 and 4,922,517 to West, Jr. et al.and U.S. Pat. No. 4,737,975 to Shafer.

While effective for their stated purpose, these landline emulatorinterfaces have a number of significant disadvantages which render themineffective in certain desirable applications. First, these interfacesreduce connected computing devices to the "least common denominator"control functionality of an old-style mechanical telephone. Thus,although a computer and modem connected to such an interface are capableof sophisticated control functions, and the microprocessor-controlledcellular telephone is capable of performing a variety of functions andproviding digital status information, a two-wire standard analogtelephone interface provided between these two microprocessor systemsdoes not permit sophisticated interaction between the connected systems.In addition, these landline jack emulation interfaces inherently includecostly and power-hungry circuitry such as dial tone generators. Finally,connecting a modem to a cellular telephone using such a system does notfacilitate a high level of integration and portability which is neededto make portable data transmission practical for a variety of users.Specifically, the systems involve additional cables, circuit boards,housings, and external power supplies which must be transported by theuser.

U.S. Pat. No. 4,837,812 to Takahashi et al. shows a facsimile machinewhich works with both a wireline telephone and a radiotelephone. Avariable resistor is adjusted to provide the correct output level forthe radiotelephone. The Takahashi machine is automatically switched fromwireline to radio transmission modes depending on the hook status of theconnected telephone sets. Takahashi does not include any enablingdisclosure of radiotelephone dialing controlled by the fax machine.

U.S. Pat. No. 4,868,863 to Hartley et al. shows an interface forconnecting a modem to a variety of country-specific landline telephonesystems and suggests that a modem might be configured to provide eitherdigital or analog output, but does not provide a system for connecting amodem to control a radiotelephone.

With the development of additional types of alternative telephonesystems, such as airplane seat telephone systems, digital cellulartelephone systems, low power personal telephone systems, and others, thedeficiencies of prior art interface schemes have become even moreapparent, since the number of interfaces that must be purchased andtransported by a person wishing to transmit data using these systems canbecome quite large.

U.S. Pat. application Ser. No. 07,531.762 for "System and Method forInterfacing Computers to Diverse Telephone Networks", assigned to theassignee of the present application, discloses a novel interface schemein which a standardized modem transmits analog data signals and genericdigital command signals through a single jack. When connected to alandline telephone jack, the jack produces standard landline DTMFsignals and transmits tip and ring data signals. An external interfacecable specifically designed to be compatible with one or morealternative telephone system telephones can also be connected betweenthe modem jack and such telephones. When so connected, the modem usesits generic digital command language to control the telephone, and thesegeneric commands are translated into control signals appropriate for theparticular telephone bus by circuitry located in the interface cable.

This interface scheme represents a significant advance over prior artinterface schemes, because one relatively simple modem can be used withvirtually any type of telephone system or telephone. The interface cableof this system, which is the part of the interface hardware that isspecific to the particular telephone, is lightweight, inexpensive tomanufacture compared to prior art interfaces, and can be powered byeither a portable computer battery or portable telephone battery withoutadversely effecting battery operating time. However, if a modem of thistype is to be used with a large number of different alternativetelephone systems such as the aforementioned systems currently underdevelopment, the use of a cable incorporating conversion circuitry andprocessing capacity becomes less desirable, because of the expenseinvolved in constructing the cables. Therefore, there is a need for aninterface system and method for connecting a standardized modem to avariety of different telephone systems without intermediate signalprocessing hardware.

SUMMARY OF THE INVENTION

Therefore, it is a general object of the present invention to provide asystem including a general purpose modem capable of functioning with avariety of differing telephone systems.

A further general object of the present invention is to provide a methodfor operably connecting a modem to a variety of differing telephonesystems.

Another object of the present invention is to provide a modem having asingle connector jack for connection to a variety of telephone systems.

Yet another object of the present invention is to provide a computermodem which can connect to a variety of telephone systems by means ofprogrammable digital input/output lines which operate differentlydepending on the requirements of the particular telephone deviceconnected to the modem.

Another object of the present invention is to provide a system fortransmitting data suitable for use with a plurality of differingtelephone system access devices, in which a computer is provided withsoftware and a modem with a plurality of general purpose connectionlines, such that a user can select the type of telephone access deviceusing the software, whereupon the modem is controlled so that itsgeneral purpose connection lines take on the specific operatinginterface characteristics required by the connected telephone accessdevice.

It is also an object of the present invention to provide a computermodem having an output jack which incorporates tip and ring lines andalso digital data lines, so that by connection of an appropriate cablethe modem can be used with a landline telephone system or with analternative telephone system.

A further object of the invention is to provide a computer modem with amemory for storing a plurality of telephone system software drivers,which may be selectively activated to use the modem with a plurality oftypes of telephone systems.

Another object of the present invention is to provide a system includinga computer with communications software and a modem with areprogrammable memory device and a universal programmable telephonesystem connection jack.

Still another object of the present invention is to provide a systemincluding a computer with communications software and a modem with areprogrammable memory device and a universal programmable telephonesystem connection jack, wherein the communications software operates toselectively download into modem memory software drivers for the desiredtelephone system or systems, and wherein the modem can be selectivelyoperated using one of such software drivers to control call placementfunctions of a variety of telephone systems.

A further object of the present invention is to provide a method ofconnecting a standardized modem to a plurality of types of telephonesystems in which the modem has a plurality of multipurpose programmabledigital control lines for controlling a connected telephone terminal,and the functions of the control lines are selected by modem controlsoftware according to the operating characteristics of the terminal.

These objects and others are achieved in the present invention byproviding a system comprising a portable computer with a centralprocessing unit and associated software. The computer furtherincorporates a modem with an output jack carrying data transmit (TX),data receive (RX), tip, ring, and programmable digital input/output(DIO) lines. A sufficient number of programmable digital input/outputlines are provided to facilitate control of a large number ofalternative telephone access devices. The operation and functions of thetip, ring, TX, RX and programmable DIO lines are controlled by softwarein the modem under the control of the software in the computer. Thefunctionality of each line at any time depends on the type of telephonedevice connected to the modem. In a preferred embodiment, a useroperates the software in the computer to specify a type or model oftelephone access device being used with the modem, whereby the RX, TX,tip and ring lines are rendered either operable or inoperable, and arequired subset of the programmable DIO lines are caused to operate in amanner necessary to achieve interactive control of an attached telephoneaccess device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a is a block diagram showing the system of the present inventionconnected for use with a radiotelephone, while FIG. 1b is a blockdiagram showing the same system connected for use with a landlinetelephone system.

FIG. 2 is a flowchart showing the operation of the computer softwareused in the system to select the telephone access device to beconnected, and thus the system's mode of operation.

FIG. 3 is a schematic diagram of the modem of the present invention witha cable providing operative connection to a first type of radiotelephone.

FIG. 4 is a flowchart showing the steps performed by software in themodem or the computer to control the operation of the lines for theconnection shown in FIG. 3.

FIG. 5 is a schematic diagram showing the modem of the present inventionand a cable for connecting this modem to a standard landline telephonejack for use with the landline telephone system.

FIG. 6 is a flowchart showing the steps performed by software in themodem or the computer to control the operation of the lines for theconnection shown in FIG. 5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring first to FIGS. 1a and 1b, a portable data communicationssystem according to the present invention is shown generally at 102.Portable data communication system 102 is configured for use with aradiotelephone in the embodiment of FIG. 1a, while portable datacommunication system 102 is configured for use with a landline telephonesystem in the embodiment of FIG. 1b. In both embodiments, system 102comprises a computer 104 which incorporates CPU 106, software 108, andmodem 110.

Computer 104 may be any type of computer. In a preferred embodiment,computer 104 may be an IBM-Compatible portable computer running underthe Microsoft MS-DOS operating system, and CPU 106 may typically be oneof a number of microprocessors manufactured by Intel in the 80×86series. CPU 106 is connected to access software 108, which is containedin a memory device such as a random access, read-only or reprogrammablepermanent memory, or on a mass storage device such as a magnetic diskdrive, optical disk drive, or bubble memory. Of course, those skilled inthe art will recognize the computer 104 also has a large number of otheroperating components connected to CPU 106. For example, various memoryand mass storage devices, input and output ports, auxiliary processors,and necessary supporting components may be provided. Computer 104 alsopreferably has means facilitating user interaction with and control ofcomputer 104, such as an information display screen, and a keyboard ortouch screen. As this other associated hardware is generallyconventional, it is omitted from drawing FIGS. 1a and 1b for clarity andwill not be described in greater detail.

CPU 106 is connected to a novel modem 110 which has a port 112 forconnecting the modem to a telephone network access device. Preferablymodem 110 is integrated into a main circuit board of the computer 104 oris constructed on a separate circuit board and installed in a card slotprovided for that purpose in computer 104. However, modem 110 could alsobe constructed for external connection to computer 104. Modem port 112preferably takes the form of a standard RJ-45 telephone connector having8 pins.

In the embodiment of FIG. 1a, port 112 is connected by a cable 114 to aconnector 118 of an access device 116 which is a terminal device forconnection to an alternative telephone system. The term "alternativetelephone system" will be used herein to define communications systems,other than traditional analog landline telephone systems, which permittransmission of information between a first station and any of a largenumber of other stations which can be selected by the first stationthrough a "dialing" or equivalent station designating operation. Theinvention will be described herein using the example of a cellularradiotelephone system, and terminal 116 will thus be referred to as"radiotelephone" 116. However, it should be recognized that theinvention is not so limited and could be used with any alternativetelephone system now existing or developed in the future includingcellular telephones, low power personal telephones, satellite-basedtelephones, airplane seat phones, and other types.

Radiotelephone 116 is conventional and includes a control unit 120, atransceiver 122 and a connecting bus 124 between control unit 120 andtransceiver 122. Connector 118 permits external connection to one ormore lines of bus 124. Radiotelephone 116 may be an integrated hand-heldunit, or control unit 120 and transceiver 122 may be contained inseparate housings and bus 124 may include a connecting cable forconnecting control unit 120 and transceiver 122. If radiotelephone 116is an integrated hand-held radiotelephone, connector 118 will generallybe a proprietary connector located in the housing of radiotelephone 116which provides external access to selected data and control lines of bus124. If radiotelephone 116 is constructed with multiple separatehousings, connector 118 may be implemented as a tap inserted in theconnection between control unit 120 and transceiver 122.

Connecting cable 114 is provided on one end with an RJ-45 connector forconnecting to modem port 112, and on the other end with a connectorcompatible with connector 118. Connecting cable 114 carries a receivedata line (RX) 126, a transmit data line (TX) 128, and one or moreprogrammable digital input/output (DIO) lines 130.

It should be noted that while the preferred embodiment of the connectionbetween radiotelephone 116 and modem 110 has been described, otherembodiments are possible. For example, parallel digital transmissionlines could be provided for RX and/or TX functions. Also, a wirelessinterface such as a radio or infrared transmitter and receiver could besubstituted for the hardwired connection shown in the preferredembodiment.

The inventor has determined that most telephone network access devicesfor alternative telephone systems, such as radiotelephone 116, can becontrolled using only a few variable function programmable digitalinput/output lines 130. In particular, it has been found that a largenumber of alternative-type telephones can be effectively controlled andmade to operate for data transmission and reception purposes using RXline 126, TX line 128, and up to three programmable DIO lines 130.However, a larger number of DIO lines 130 could also be providing byusing a second connector in addition to the RJ-45 connector, or a singleconnector with a larger number of pins. In one secondary embodiment, thelines carried by modem port 112 are divided and carried by a pluralityof connectors. For example, tip and ring lines carried by modem port 112could be carried in a standard RJ-11 jack and RX line 126, TX line 128,and programmable DIO lines 130 could be carried in a separate connector,such as an RJ-45 connector.

Modem 110 can be configured to provide a variety of input and outputsignals on DIO lines 130, depending on the type of alternative telephone116 being used. Then, by providing an appropriate cable 114 forconnecting modem 110 and alternative telephone 116, a user can transferdata using computer 104 in conjunction with an alternative telephonenetwork. Specifically, in a preferred embodiment, a user can operatecomputer 104 using special software 108 to select the type of telephone116 that will be used. Appropriate portions of software 108 may then beloaded into modem 110 and selected for use. In this way, the linescarried by cable 114 effectively control the operation of telephone 116in placing calls and transmitting and receiving data. Modem 110 can thusbe used with any type of alternative telephone system, includingcellular telephones, low power personal telephones, airplane seatphones, satellite telephones, and other types of telephone systems nowavailable or which may be developed in the future. Modem 110 willpreferably operate using a variety of protocols depending on thecharacteristics of the telephone system being used to transmit data.When used with a cellular telephone system, modem 110 will preferablyoperate with the protocols disclosed in U.S. Pat. No. 4,697,281 owned bythe assignee of the present invention, the disclosure of which isincorporated herein by reference.

As shown in FIG. 1b, computer 104 incorporating modem 110 can also beconnected to a landline telephone interface 132 which is a telephonenetwork access device for landline telephone systems. As indicatedpreviously, modem port 112 is preferably provided in the form of anRJ-45 connector. Landline telephone interface 132 may take the form ofan RJ-11 wall plug providing tip and ring connections to a localtelephone central office. Cable 134 is connected between the RJ-45connector of modem port 112 and the landline interface 132 to connectthe tip and ring lines of modem port 112 to the tip and ring linesrespectively of landline telephone interface 132. Preferably, pins 4 and5 of the RJ-45 connector of modem port 112 are assigned to the tip andring lines, so that cable 134 may be a standard landline telephone cablehaving RJ-11 connectors at each end. Thus, modem 110 providescompatibility with a wide variety of alternative telephone systems,while maintaining backward compatibility with the analog tip and ringlandline telephone system. The operation and programming of modem 110may further incorporate the teachings of allowed U.S. patent applicationSer. No. 07/531,762, filed Jun. 1, 1990 entitled "System and Method forInterfacing Computers to Diverse Telephone Networks", the disclosure ofwhich is incorporated herein by reference. When computer 104 and modem110 are connected to a landline telephone interface 132 as shown in FIG.1b, modem 110 will generate standard dual tone multi-frequency (DTMF)telephone control signals on the tip and ring lines to place calls, andwill then transfer data over the tip and ring lines. When connected toan alternative telephone system, such as radiotelephone 116 as shown inFIG. 1a, modem 110 will generate digital control signals to control callplacement. The control signals generated will be transmitted overprogrammable DIO lines 130 and/or the RX line 126 and TX line 128 andwill be specific to the type of alternative telephone being used asselected by the software.

Software 108 is a dedicated communications program which initiates andcontrols the operation of modem 110. A primary function of software 108is the selection and loading into modem 110 of drivers for particulartelephone devices to be used with system 102. The term "driver" will beused herein to define any combination of program instructions and/ordata which is specific to a particular brand, model, or type oftelephone network access device. In one embodiment, a separate dedicatedsoftware driver program is provided for each telephone device which willbe used with the system.

In another embodiment, a specific driver program is provided forlandline telephone systems and a generalized driver program is alsoprovided for accessing alternative-type telephone systems. Thegeneralized driver program operates using a data table which has driverdata defining the interface scheme of various alternative-type telephoneaccess devices. The generalized program operates appropriately with aparticular alternative-type telephone device by referring to this datatable and retrieving the necessary information at each step of theprogram. A typical list of data elements sufficient for the performanceof some of the basic functions of system 102 is provided in Table 1. Inmany cases, the data table will include bit masks which identify whichof the RX, TX, and DIO lines will be used to perform a particulartransmission or sensing function. Since there are fewer than eight ofthese lines in the preferred embodiment, a single byte bit mask will besufficient to define the function of these lines as to a particularoperation. The basic list of data elements provided in Table 1 can beexpanded as desired to include any information about the telephone thatis needed to perform a desired operation.

                  TABLE 1                                                         ______________________________________                                        GENERALIZED DATA TABLE ELEMENTS                                               ______________________________________                                        Data Elements for Model/Type Identification                                   Mask for interfaced lines which are normally high                             Mask for interfaced lines which are normally low                              Mask for interfaced lines which normally alternate                            between high and low levels                                                   Data Elements for Checking Bus Availability                                   Mask for lines which must be high before taking control                       of bus                                                                        Mask for lines which must be low before taking control                        of bus                                                                        Data Elements for Taking Control of Bus                                       Mask for I/O lines to be given a "high" level to take                         control of bus                                                                Mask for I/O lines to be given a low level to take                            control of bus                                                                Mask identifying lines used for serial digital                                transmission                                                                  Mask identifying lines used for serial clocking                               operations                                                                    Data to be serially transmitted to take control of bus                        Data which should be received from phone                                      Data identifying protocols, i.e. clock high to low,                           which operation should be performed first, etc.                               Mask for I/O lines to be given a "high" level to disable                      speaker and microphone                                                        Mask for I/O lines to be given a "low" level to disable                       speaker and microphone                                                        Data Elements for Performing Dialing and Data Operations                      Mask identifying line or lines to be used for                                 transmissin                                                                   Data indicating audio level for transmission                                  Initial data to be transmitted                                                Data to be transmitted to dial "0"                                            Data to be transmitted to dial "1"                                            .                                                                             .                                                                             Data to be transmitted to dial "9"                                            Data to be transmitted to "send" dialed digits                                Data to be transmitted to "end" call                                          Data on acknowledgement signals to be received, if any                        Ending data to be transmitted                                                 ______________________________________                                    

The driver software for a particular telephone device will generally bedownloaded into storage memory of modem 110 (for example, "flashupgradeable memory") before that telephone device is used with modem110. The choice of design for the driving software is dependent on thenumber of telephone devices which are to be used with a single modem110. If a very large number of telephone devices are to be used, thememory required to hold separate driver programs for each telephone willalso be large, and it will be desirable to provide a generic operatingprogram which operates using a data table for each telephone device, asshown in Table 1. Preferably, the memory of modem 110 will hold severaldifferent drivers at the same time and will permit replacement orupgrading of the drivers as needed.

A generalized flowchart for software 108 is shown in FIG. 2. Upontransfer of control of CPU 106 to software 108, the program firstdetermines what type and model of telephone is to be used for acommunications session as shown in block 150. Preferably, a defaultselection will be provided for the user based on past usage patterns orbased on the connection of a particular cable or the receipt oftelephone-bus-specific signals as sensed through modem port 112. If thecable is sensed, a default may be provided in each general class ofdevices, i.e. one default for tip-and-ring devices and one default foralternative telephone devices. If driver information for particulartelephones has been previously downloaded into the memory of modem 110,this information may also be used in determining the default. Forexample, if modem 110 has driver information stored for landlinetelephones and for a NEC P300 cellular radiotelephone, then sensing ofthe connection of a cable to lines of modem port 112 other than the tipand ring lines will cause the NEC P300 driver to be selected as thedefault.

If actual bus signals are sensed, rather than merely general cableconnections, software 108 may be able to identify or at least narrowdown the particular model of telephone device being used based onrest-state signal levels transmitted by the bus 124 of thealternative-type telephone. That is, certain lines may be driven "high"or "low" by the telephone. A bit mask defined for each alternative-typetelephone could be compared with the bit pattern sensed on the RX, TX,and DIO lines to narrow down or positively determine the type oftelephone connected.

It is possible to provide software 108 with drivers for all commerciallyavailable alternative-type telephones. However, maintaining anddistributing up-to-date driver sets would be cumbersome, and might notprovide substantial benefits since any given user will typically accessonly a few alternative-type telephones. Therefore, in the usual case,driver software for the landline telephone system will be built intosoftware 108, and driver software specific to particularalternative-type telephones may be provided in a separately purchasedpackage along with an appropriate cable 114. Thus, only a few (perhapsone to ten) drivers for the telephone devices normally used by the userwill be available in the system, and it may be possible to exclude allbut one possible identity of the telephone device connected by fairlyrudimentary sensing of the telephone device bus lines.

Preferably, the user may view a menu of telephone devices for whichdrivers are available in the system 102 and select a device to be usedor designate new default telephone devices.

When the default telephone device has been accepted by the user or adifferent driver has been manually chosen, software 108 determineswhether the required driver exists in modem memory as shown at block152. If the selected driver is not available to the modem, software 108will preferably download the driver to the modem memory as shown inblock 154. Preferably, the driver software will be stored innon-volatile memory so that downloading is only required during thefirst operation after the user has obtained access to a new telephonenetwork access device, and is not necessary each time modem 110operates. However, if desired, software 108 could instead operate todownload the required driver to volatile RAM in modem 110 each timesoftware 108 is activated.

After software 108 ensures that the necessary driver is available, thedriver is designated as the operative driver in block 156, for exampleby defining pointers to the memory locations of the desired driverinstructions and/or data. Modem 110 is thus set to operate with theselected driver.

Next, in block 158, software 108 transmits to modem 110 instructionsdefining the desired operation. For example, if a data transfer call isto be placed to the number 555-1234, an instruction (preferably part ofa predefined or standardized modem instruction set) to this effect wouldbe transmitted by computer 104 to modem 110.

Then, in block 160, software 108 operates to transfer digital data ineither or both directions between the computer 104 and a remote modemdevice through the connected telephone system. This transfer ofinformation may be accomplished by a number of methods well known in theart, which may incorporate "script" processing functions, file transferfunctions, or the computer 104 may be placed in a terminal emulationmode for interactive communication with the remote device.

Of course, those skilled in the art will recognize that the system ofthe present invention could be made to perform the same operations withprocessing, memory, and software configurations other than the preferredconfigurations described herein. For example, modem 110 could becontrolled from, and the driver software could be resident in, computer104 rather than being downloaded to modem 110. This mode of operationwould be preferred if the modem 110 is integrated onto the main board ofcomputer 104.

FIG. 3 is a block schematic diagram of modem 110 and cable 114 of FIG.1a, configured for use with an NEC Model P300 Cellular telephone 116.Modem 110 comprises a computer connection port 202, controller 204,memory 206, data pump 208, operational amplifiers 210 and 212, isolationtransformer 214, hook switch 216 and various associated resistors andcapacitors for performing biasing, loading, isolating, and levelmatching functions in the circuit. Controller 204, memory 206, and datapump 208 are conventional. For example, controller 204 may be a RockwellC19, memory 206 may be a Toshiba TC55257, and data pump 208 may be aRockwell R6634.

Modem port 112 has eight lines terminating in an externally accessibleRJ-45 connector. Pin 8 of this connector is connected to RX line 218,which is operatively connected to an RX-In terminal of data pump 208 andalso to a first I/O port of controller 204. Pin 7 is connected toground. Pin 6 is biased to +5 volts DC by a connection to a power sourcethrough a resistor and is operatively connected by DIO line 220 to asecond I/O port of controller 204. Pin 5 of the RJ-45 connector isconnected through hook switch 216 and the primary winding of isolationtransformer 214 to pin 4 of the RJ-45 connector. The secondary windingof isolation transformer 214 is connected through operational amplifiers210 and 212 to the RX-In and TX-Out pins of data pump 208. Pin 3 of theRJ-45 connector is connected by DIO line 222 to a third I/O port ofcontroller 204. Pin 2 of the RJ-45 connector is biased to 0 volts by apull-down resistor connected to ground, and is further connected by DIOline 224 to a fourth I/O port of controller 204. Pin 1 of the RJ-45connector is connected by TX connecting line 226 to the TX-Out terminalof data pump 208 and to a fifth I/O port of controller 204. Additionalconventional tip and ring interface circuitry not shown in the diagrambut well known in the art may also be provided, such as a ring voltagedetector circuit.

The RX-In and TX-Out pins of data pump 208 are thus connected throughappropriate interface circuitry to the tip and ring lines (pins 4 and 5of the RJ-45 connector) to facilitate transfer of data using aconventional tip and ring interface. The RX-In and RX-Out pins are alsooperatively connected to RX and TX lines of the RJ-45 connector,respectively. Thus, a two-wire to four-wire conversion means is providedfor operatively connecting the two wire analog data interface of datapump 208 simultaneously to a tip and ring interface and also to an RX-TXinterface.

Hook switch 216 is provided for selectively connecting the tip and ringlines to create an on-hook or off-hook condition, and operates undercontrol of the controller 204 by a connection which is omitted from thedrawing for clarity. Although not shown in the drawing, isolationswitches can also be provided for the RX and TX pins of the RJ-45connector, operating under control of controller 204, to preventtransfer of signals through the RX and TX lines when the tip and ringinterface is in use, and vice versa. Thus, controller 204 is providedwith a means for selectively activating either a tip-and-ring styleinterface or an RX-TX style interface depending on the requirements ofthe attached telephone device. However, in the preferred embodiment,both the RX/TX and tip-and-ring interfaces are activated and operablewhenever modem 110 is activated, and the interface that is used forcarrying data is determined by the connections made by cable 114 orcable 134. Preferably, the cables used with the system will operablyconnect either the RX/TX lines or the tip-and-ring lines to a telephonedevice, but not both.

The data pump 208, through its connection to the tip-and-ring or RX-TXlines, provides analog data transfer capability. Significantly, inaddition to selecting the interface standard, controller 204 canselectively operate the modem 110 in either an analog or digital datatransfer mode. This capability is facilitated by the connection of theRX pin 8 and TX pin 1 of the RJ-45 connector to the first and fifth I/Oports of controller 204. Controller 204 may selectively deactivate datapump 208 and activate its first and fifth I/O ports to transfer data inserial digital form over the RX and TX lines of modem port 112. As aresult, modem 110 of the present invention can be used with telephonesystems which use analog data transmission, such as public cellularradiotelephones, and also with systems using digital transmission, suchas certain digital cellular telephones currently under development whichincorporate their own modulation and demodulation devices fortransmitting digitized voice signals.

The connection of I/O ports to the RX and TX lines also permits sensingthe presence of signals on these lines, particularly when the modem 110is not transferring data. For example, a ringing signal may be generatedon the speaker line of radiotelephone 116 which is connected to the RXline, and this signal could be sensed by controller 204 to initiate acall answering sequence of modem 110. This I/O port connection alsofacilitates biasing of the RX and TX lines which, as will be seen, isdesirable for controlling alternative telephone operation.

Computer connection port 202 provides an operative connection tofacilitate interactive control and transfer of data between modem 110and computer 104 (shown in FIGS. 1a and 1b). Port 202 may be a serialport, a parallel port, a bus connection, or have any other appropriateconfiguration depending on the interface provided in the design ofcomputer 104 for the connection of modem 110. Port 202 is operativelyconnected to controller 204, which is operatively connected by aplurality of lines to both data pump 208 and memory 206. Memory 206provides read/write storage of data during modem operation, and alsoprovides permanent or semi-permanent storage for operating software ofmodem 110. Preferably, memory 206 may incorporate "flash upgradeablememory" which can be loaded or reloaded with a particular desired set ofinstructions which are then retained in memory 206 until replaced in asubsequent programing operation.

In this first example, the modem 110 is configured for use with an NECModel P300 cellular telephone. Those skilled in the art will recognizethat based on the disclosure herein, similar configurations could beprovided for a variety of cellular and other alternative telephones.

Cable 114, as shown in the inset of FIG. 3, is provided with an RJ-45plug 228 at one end and a type 2303 connector 230 at its other end. TheRJ-45 connector 228 mates with the RJ-45 jack of modem port 112, and thetype 2303 connector 230 connects to a mating connector 118 on the NECP300 cellular telephone 116. The pin connections of cable 114 are shownin FIG. 3, and also in Table 2.

                  TABLE 2                                                         ______________________________________                                        CABLE CONNECTIONS FOR NEC P300                                                RJ-45           2303                                                          PIN       NAME      PIN         NAME                                          ______________________________________                                        1         TX        8, 3        TXAF                                          2         DIO        4          DATA                                          3         DIO       10          BUSY                                          4         RING                                                                5         TIP                                                                 6         DIO       11          SCK                                           7         GROUND     9, 12      GROUND                                        8         RX         2          SPK                                           ______________________________________                                    

Through the design of cable 114, DIO lines 130 are connected to theparticular lines of cellular bus 124 of radiotelephone 116 which must beactuated to control the placement and reception of calls usingradiotelephone 116. As shown in the diagram, for certain telephones suchas the NEC P300, the number of lines of cellular bus 124 to be actuatedmay be greater than the number of programmable DIO lines 130 provided bymodem port 112. In such cases, as in the example shown here, TX line 128and RX line 126 may be connected to more than one line of bus 124, suchas through biasing resistors. Preferably, the lines of bus 124 whichshare a single line from modem port 112 are grouped so that the signalsthey require need not be provided at the same time as signals to otherlines of bus 124 connected to the same line of modem port 112.Alternatively, if such a grouping is not possible, TX line 128, inparticular, can be used to bias a line of cellular bus 124 which is tobe held at a high level during data transmission. TX line 128 can thenbe held high during periods when no data is transmitted. In many casesthe brief drops of TX 128 to a low level during data transmission maynot adversely effect the operation of cellular bus 124 since internalcapacitance may prevent the additionally connected biased line ofcellular bus 124 from becoming unbiased by the toggling of TX line 128.

The function of the various lines of the NEC P300 cellular telephone'sconnector 118 will be described only in general terms herein sufficientto promote an understanding of the present invention. Those skilled inthe art will recognize that the construction and programming of thesystem of the present invention to work with any specificalternative-type telephone must be performed with reference to the businterface specification of the particular alternative telephone which isto be used, as defined by the manufacturer of that telephone. Forexample, for the NEC P300 cellular telephone, the "TR5E-800-21Adata/audio interface specification" produced by NEC America providesspecifications for the precise signal sequences to be transmitted toexternally control the NEC P300 telephone, and is incorporated herein byreference. The signals and sequences required vary depending on themanufacturer and model of telephone to be used, and are not part of thepresent invention.

In the example of FIG. 3, RX pin 8 is connected to SPK pin 2 which is anaudio output or "external speaker" line of bus 124. DIO pin 6 isconnected to SCK pin 11, which is a serial clock line which is biasedfrom high to low by either the telephone or an external device toindicate the presence of valid data on DATA pin 4. HFRAST pin 3 can bebiased to +5 volts DC to disable the microphone and speaker of telephone116. The level of BUSY pin 10 can be raised and lowered to indicate thepresent availability of bus 124. DATA pin 4 is a bi-directional serialdigital data line capable of transmitting and receiving signals toindicate the status of radiotelephone 116 and to initiate operationssuch as call placement operations under external control. TXAF pin 8 isan audio signal input line which accepts an analog microphone signal.

The operation of modem 110 to initiate a call and the transmission andreception of data using the NEC P300 cellular telephone will now bedescribed with reference to the flowchart of FIG. 4. The flowchart ofFIG. 4 shows the steps performed by a software routine stored in memory206 and performed by controller 204 in response to a program initiationsignal received through port 202 from computer 104. The software routineused may be provided specifically for the NEC P300, or a generalizedprogram may be provided, along with a data table which defines theinterfacing scheme of the NEC P300 so that the generalized softwareprogram can operate with the NEC P300 as described herein.

FIG. 4 shows the steps performed by the software of modem 110 to place acall and transfer data using an alternative telephone network accessdevice. These steps will be described with particular reference to theexample of FIG. 3 which uses an NEC P300 cellular telephone 116 as thealternative telephone network access device. In the first step, shown asblock 302, the modem verifies that radiotelephone 116 is connected andready to operate. One or more of the lines of modem port 112 (shown inFIG. 3) may be sensed by controller 204 to determine whether cable 114has been properly installed to connect modem 110 to radiotelephone 116.Modem 110 can determine whether radiotelephone 116 is ready to receivecontrol instructions by sensing the status of the BUSY line ofradiotelephone 116. A low signal level on the BUSY line indicates thatradiotelephone 116 is not available to receive commands.

When modem 110 has determined that radiotelephone 116 is connected andready to operate in placing a call to transfer data, modem 110 willdisable the microphone and speaker of radiotelephone 116 as shown inblock 304 of the flowchart of FIG. 4. The microphone of radiotelephone116 is disabled to prevent ambient noise from interfering with thetransmission of data. The speaker of radiotelephone 116 is disabled sothat the user is not forced to listen to a data carrier and/or modulateddata signal over the speaker of radiotelephone 116. In the example shownusing the NEC P300, the disabling of the microphone and speaker ofradiotelephone 116 is accomplished by biasing RX line 126 to +5 volts DCusing the connected first I/O port of controller 204, and biasing the TXline 128 to +5 volts DC by placing a "high" level signal on the secondI/O port of controller 204. Biasing the RX and TX lines to +5 volts DCplaces a high level signal on the SPK, HFRAST, and TXAF lines of the NECP300 which has the effect of disabling the microphone and earpiece andactivating the transfer of audio signals to connector 118.

As shown in block 306, the software of modem 110 then sets the audiooutput level of data pump 208 to the proper level for analog receptionand transmission of data over the RX line 126 and TX line 128respectively. For the NEC P300 cellular radiotelephone, an audio levelof -28 dB is preferred. However, for other cellular radiotelephones orother type alternative telephones, different audio levels willcustomarily be required. Because data pump 208 is capable of adjustingits audio level in response to software-driven commands of controller204, it is possible to use modem 110 with a wide variety of alternativetelephones. If the alternative telephone is one which includes its ownmodulating and demodulating device similar to data pump 208, modem 110may transmit and receive digital signals over the RX and TX lines usingthe I/O ports of controller 204 as described previously. If operation inthis mode is desired, the audio level of data pump 208 will be set to 0,i.e. the data pump 208 will be disabled. If the audio level required bythe connected telephone is lower than the range of the data pump 208used in the circuit, a resistor can be provided in the RX line 126 incable 114 to reduce the output voltage.

Having optimized the functions of modem 110 for the particularalternative telephone in use, modem 110 will then transmit commandsignals to initiate a telephone call, as shown in block 308 of FIG. 4.The commands will be transmitted by assigning particular functions tothe DIO lines 130 according to the type of alternative telephone in use.In the case of the NEC P300 cellular radiotelephone 116, theprogrammable DIO lines 130 are connected to the SCK, BUSY, and DATAlines of bus 124 of radiotelephone 116. It will be recognized that thesoftware-controlled function of the DIO lines 130 will be selecteddepending on the characteristics of the alternative telephone devicebeing used. In addition to the connections required, the precise signals(and the timing of the signals) which are transmitted to the alternativetelephone device to produce the desired operations, will be determinedwith reference to the interface specification which is defined by themanufacturer of the particular alternative telephone device. In the caseof the NEC P300 cellular radiotelephone, dial commands will betransmitted according to the signal definitions provided in the NECData/Audio Interface Specification previously referenced. In general,for the NEC P300 cellular radiotelephone 116, modem 110 will provide adial command by pulling the BUSY line low to gain control of the bus,and then transmitting the command in serial digital fashion to the DATAline, providing a clocking signal for the serial data transmission onthe SCK line. Typically, the dial commands may take the form of keypressemulating commands available in the command set of the alternativetelephone system. For example, to dial the telephone number 555-1234using the NEC P300 cellular radiotelephone 116, modem 110 wouldsequentially transmit keypress emulating commands on the DATA line foreach of the 7 digits of the telephone number, beginning with 5 andending with 4. Modem 110 would then transmit a command on the DATA lineto emulate the pressing of the "send" key on radiotelephone 116. As aresult, radiotelephone 116 will perform the operations it would haveperformed if the user had dialed the number on its keypad and pressedthe "send" key, resulting in the placement of a call to the specifiedtelephone number.

In the next step of the flowchart of FIG. 4, in block 310, modem 110determines whether a connection has been made to the selected telephonenumber. This determination is made by receiving status information fromthe alternative-type telephone. In the case of NEC P300 cellularradiotelephone 116, call status information will be returned to modem110 on the DATA line. If the alternative telephone device is not capableof providing detailed status information, modem 110 may operate byassuming that a connection has been made and waiting for a carrier onthe RX line 126 transmitted by a corresponding modem at the dialedtelephone number. A time-out clock of, for example, 20 seconds could beprovided in this case, and if no carrier signal is received from theremote location before the end of the defined period, modem 110 willassume that the connection attempt has failed and operate accordingly.Specifically, in the case of a connection failure, control will transferto block 316 of FIG. 4 whereupon modem 110 will transmit a command tothe alternative telephone directing it to end the call placementattempt. In the case of the NEC P 300 cellular radiotelephone 116, acommand to emulate the pressing of the "end" key could be transmitted.Then, as shown in block 318, modem 110 will reset its internal operationand release its control over bus 124 of radiotelephone 116. In the caseof the NEC P300, modem 110 will allow the busy line to return to a"high" level to relinquish control of the bus. Preferably, modem 110will generate an indication to the user that the call has beendisconnected, or that it could not be placed.

If the connection is made, control transfers to block 312 in which datais transmitted and/or received over the TX line 128 and RX line 126respectively. Typically, this step will involve transmission andreception of carriers which must be detected by the modems at each endto allow data transmission. Also, modem 110 may negotiate protocols tobe used, including error correction protocols and speed of transmissionwith the remotely connected modem. The protocols preferred by modem 110in the negotiation will be determined by the type of telephone systembeing used. For example, in a cellular system, enhanced error correctingprotocols will be preferred because fading, interference, and hand-offsin such systems inherently cause an increased rate of errors which mustbe corrected. When the connection has been fully established in thismanner, modem 110 may transmit and/or receive data on TX line 128 and RXline 126.

Transfer of data may be accomplished by a number of general methodswhich can be selected by the user. For example, the communicationssoftware may enter a terminal emulation mode permitting directinteraction of the user with a remote computer. Alternatively, thesoftware may enter a file transfer mode for transferring data to or frommemory or a storage medium.

The transfer of data will continue until the transfer is complete asshown in block 314, either by virtue of there being no further datawhich is to be transferred, or by virtue of some interruption in thetelephone which causes a permanent interruption in the data link.Preferably, temporary interruptions such as those occurring during cellhand-offs in a cellular telephone system, will be tolerated as long assuch interruptions do not exceed a predetermined time-out determinedwith reference to the characteristics of the particular alternativetelephone system in use.

It is generally preferred to automate the placement of data transfercalls under control of the computer 104 according to the flowchart ofFIG. 4. It will also be desirable to similarly automate other linecontrol functions which are known in the modem art. For example,auto-answer capability can be provided in which the modem is placed in awaiting mode to receive data transfer calls. When the modem is in autoanswer mode and a ringing signal is received, the same general sequenceof steps will be performed as described with reference to FIG. 4, butthe commands transmitted to the alternative-type telephone in block 308will be commands to answer the incoming call, rather than to place acall. Although less preferred, it is also possible to provide only aminimal capability of modem 110 to control a connected alternative-typetelephone. For example, in the flowchart of FIG. 4, blocks 308 and 316could be eliminated, and call placement and termination would then bemanually performed by the user using the controls of thealternative-type telephone. Modem 110 would still operate to disable themicrophone and speaker and take control of the telephone bus after thecall is placed, and would then release the bus and enable the microphoneand speaker after completion of the data transfer.

In addition to having a plurality of functional modes permittingselective operation with a variety of alternative-type telephonesystems, modem 110 can be used with a standard landline telephonesystem, as will be described with reference to FIG. 5. FIG. 5 showsmodem 110 operatively connected to a landline telephone system in theconfiguration shown previously in FIG. 1b. Pins 1-3 and pins 6-8 of theRJ-45 connector of modem port 112 are not connected in thisconfiguration. The tip and ring lines (pins 4 and 5 respectively) areconnected to tip and ring lines of a standard landline telephone walljack by a cable 134 having RJ-11 connectors at each end. To accommodatesuch a connection, the RJ-45 connector of modem 110 is preferably of thetype which will accommodate insertion of other RJ-45 connectors, andalso a centered insertion of an RJ-11 connector having a slightly lesserwidth and 6 pins rather than 8. Thus, pins 4 and 5 of the RJ-45connection of modem port 112 will be connected to the third and fourthpins respectively of a 6-pin RJ-11 connector inserted in the RJ-45 jack.

The operating software of controller 204, which as described previouslymay be stored in memory 206, provides for different operating parametersin the configuration of FIG. 5 than are provided in the configuration ofFIG. 3. As noted previously, the software provided may either include aseparate program for landline operation, or may be generalized, in whichcase a data table will be provided with the program specifying whichfunctions are to be performed and which lines are to be used forparticular functions, so as to provide the operation described hereinwith respect to landline telephone systems. FIG. 6 shows a flowchartdefining the functions of the software of modem 110 in placing alandline call when modem 110 is connected to a landline telephone systemas shown in FIG. 5. In block 502 of the flowchart, the call placementfunction begins with verification that the landline telephone system isconnected and ready for use by the modem in placing a call. Typically,this verification function may be performed by taking the landlinetelephone line off hook using hook switch 216, and detecting thepresence or absence of a dial tone on the tip and ring lines. Thisoperation thus differs from the operation defined in block 302 of FIG. 4in that no digital data interchange occurs between modem 110 and theconnected telephone system.

Next, as shown in block 504, the data pump 208 audio level is set bycontroller 204 to an optimized level for landline telephonecommunication. In a preferred embodiment, the audio level for landlinecommunications will be set to a value in the range of -10 to -25 dB.

In block 506, dual-tone multi-frequency telephone dialing signals aregenerated by conventional circuitry associated with modem 110 andtransmitted over the tip and ring lines to the landline telephonesystem. Dualtone multi-frequency signal generation may be provided as acapability of data pump 208, or a separate DTMF generating circuit (notshown) may be provided within modem 110 and operatively connected to thetip and ring lines in a manner which is well known in the art. Thisdialing operation, in contrast to the operation of block 308 in FIG. 4,does not involve the transmission of digital control and handshakingsignals through the variable function programmable DIO lines 130, butinstead is an analog transmission of standardized DTMF telephone controlsignals over the tip and ring lines.

In block 508, modem 110 monitors the signals on the tip and ring linesto determine whether a connection has been made to the dialed telephonenumber. In particular, data pump 208 may be operated to detect a carriersignal transmitted by a distant modem at the dialed telephone number,with the receipt of the carrier signal indicating that a data transferconnection has been completed. When the data transfer connection hasbeen made, digital data to be transferred is transmitted and receivedover the tip and ring lines and the tip and ring interface circuitry ofmodem 110 by the data pump 208. Data pump 208 transmits modulatedsignals representing digital data to be transmitted through the TX-Outpin, and receives modulated signals representing digital data throughthe RX-In pin. Controller 204 receives data to be transmitted fromcomputer 104 through port 202 and passes the data to data pump 208 fortransmission. Controller 204 receives incoming data from data pump 208in digital form and transmits this data through port 202 to computer104. Controller 204 determines the error correcting and other protocolswhich are to be used in the transmission of data depending on thesoftware program. Because of the greater reliability of a hard-wiredlandline telephone system, simpler error correcting protocols whichgenerate less overhead are preferred for landline communications. Asnoted before, because systems which incorporate radio transmission ofdata are subject to interference, fading, transmitter hand-offs, andother sources of data error, more complex error correcting protocolssuch as forward error correction, variable packet sizing and othertechniques may be used with alternative-type telephone systems.

When the desired transfer of data has been completed, as shown at block512, control passes from block 510 to block 514 and controller 204operates hook switch 216 to place the tip and ring lines on hook thusdisconnecting the call. In cases where the desired call cannot becompleted for the transfer of data, control is passed from block 508 toblock 514, bypassing the transmission and reception of data, and thecall is disconnected. Preferably, in this case, controller 204 providesa signal to computer 104 to alert the user to the nature of the callfailure.

Because the DIO lines 130 can be operated variably to interface withvarious types of telephones 116, a single modem can be used with allexisting landline and cellular networks, as well as other types oftelephone networks which may come into common use. Thus, this modemeliminates the need for a computer user to have several modems. Inaddition, the standard, generic nature of the modem means that it can beproduced in very large quantities by manufacturers and stocked in smallquantities by retailers since there will be no great proliferation ofmodels. The generic nature of the modem and the fact that the modem canbe reprogrammed by software 108 introduced into computer 104, to thuswork with new and different types of access devices 116 means that modem110 can be integrated into the main circuit board of computer 104. Suchan integrated modem can be upgraded for use with new telephones andtelephone-like systems by introducing new operating software, ratherthan by replacing the modem hardware. Because of its generic nature, themodem according to the present invention can also be mass produced forlittle more than the cost of a landline-only modem. The modem accordingto the present invention contains all the complex circuitry necessary toestablish communications. Only relatively simple and inexpensiveconnecting cables need be specific to the telephone which is to be usedwith the modem. Thus, the system of the present invention furtherreduces the total end user cost of multi-network data transmissionaccess.

I claim:
 1. A system for transferring data between a computing deviceand a remote device using a selected one of a plurality of telephonenetwork access devices including at least one radiotelephone networkaccess device, comprising:modem means for connection to said computingdevice and further connectable by at least one of a receive line andtransmit line interface and a tip and ring line interface to one of saidtelephone network access devices for transferring data between saidcomputing device and a remote data transfer device over said connectedtelephone network access device, said modem means operating selectivelyto transfer digital data in one of at least two modes depending on thetype of telephone network access device in use: a first mode using saidreceive line and transmit line interface to transfer a signalrepresenting digital data, and a second mode using said tip and ringinterface to transfer an analog signal representing digital data, saidmodem means comprising:modem controller means connected to said computermeans for controlling the mode of operation of said modem means and forcontrolling call placement functions of said connected telephone networkaccess devices in response to a software driver; and memory meansconnected to said modem controller means for storing one or more of saidsoftware drivers, each including data specific to at least oneparticular telephone network access device for use by said modemcontroller means in selecting an appropriate one of said modes ofoperation of the modem and generating appropriate call placement controlcommands specific to said particular telephone network access device;and a data communications program operating in the computing device andcapable of accessing a plurality of said software drivers and thereafterselectively downloading one or more of said software drivers to saidmemory means for subsequent use in transferring data using an associatedtelephone network access device connected to said modem means.
 2. Thesystem of claim 1 wherein said memory means has the capacity to store aplurality of said software drivers.
 3. The system of claim 2 whereinsaid memory means stores a software driver for a landline telephoneconnection and at least one software driver for a cellularradiotelephone connection.
 4. The system of claim 1 wherein said memorymeans comprises flash reprogrammable memory.
 5. The system of claim 1further comprising jack means for connecting said tip and ring interfaceand said transmit line and receive line interface to said one of saidtelephone network access devices.
 6. The system of claim 5 wherein saidjack means comprises a standard telephone connector, and furthercomprising cable means extending at least between a first connectormating with said standard telephone connector and a second connectormating with a connection port of said telephone network access device.7. The system of claim 6 wherein said cable means is a standard RJ-11landline telephone cable.
 8. The system of claim 7 wherein said standardRJ-11 landline telephone cable operably connects said tip-and-ringinterface to said telephone network access device without operablyconnecting said transmit line and receive line interface to saidtelephone network access device.
 9. The system of claim 6 wherein saidfirst connector is an RJ-45 connector.
 10. The system of claim 6 whereinone said cable means operably connects one or more of said control linesand said receive line and transmit line interface to a selectedradiotelephone network access device without operably connecting saidtip and ring interface to said radiotelephone network access device. 11.The system of claim 10 wherein said cable means comprises level settingmeans for setting the signal level transmitted by said transmit line andreceive line interface.
 12. The system of claim 11 wherein said levelsetting means comprises a resistor installed in said cable means. 13.The system of claim 6 wherein a plurality of said cable means areprovided, each cable means specifically designed in conjunction withsaid software drivers to render said system operable with at least oneof said telephone network access devices.
 14. The system of claim 5wherein said jack means comprises two connectors, a first connector forconnecting to said tip and ring interface and a second connector forconnecting to said receive line and transmit line interface.
 15. Thesystem of claim 14 wherein said first connector is an RJ-11 connectorhaving six pins and said tip-and-ring interface uses the third andfourth pins of said RJ-11 connector.
 16. The system of claim 1 whereinthe receive and transmit interface operates at a specified audio level,said audio level variable under the control of said modem controllermeans according to the requirements of the telephone network accessdevice in use.
 17. The system of claim 16 wherein said software driversinclude data defining the required audio level for the selectedtelephone network access device whereby said audio level isappropriately set.
 18. The system of claim 1 wherein the modemcontroller means further comprises digital data ports operably connectedto said receive line and said transmit line respectively, whereby saidmodem controller may selectively control and monitor the signal levelson said receive line and said transmit line.
 19. The system of claim 18wherein said modem controller means selectively operates to transferdata in digital form over said receive line and transmit line interface.20. The system of claim 1 further comprising bifunctional means forselectively operating said receive line and transmit line interface in afirst mode to transfer an analog signal representing modulated digitaldata and in a second mode to transfer a digital data signal in bipolarform, the selection between said modes determined by the type oftelephone network access device in use.
 21. The system of claim 1wherein the modem controller means operates to transfer digital data inone of two modes: a first mode wherein said receive line and transmitline interface transfers a signal representing digital data, and asecond mode wherein said tip and ring interface transfers an analogsignal representing digital data, the selection of said first or secondmode determined by the type of telephone network access device in use.22. The system of claim 21 wherein said software drivers define the modeof operation to be used with a particular telephone network accessdevice.
 23. The system of claim 1 wherein the modem controller meansselectively operates the modem means in one of three data transfermodes: a first mode wherein analog signals representing modulateddigital data are transferred using said receive line and transmit lineinterface, a second mode wherein digital data signals in bipolar digitalform are transferred using said receive line and transmit lineinterface, and a third mode in which said analog signals of the firstmode representing modulated digital data are transferred using said tipand ring interface, wherein the selection between said modes isprogrammably determined depending on the type of telephone networkaccess device in use.
 24. The system of claim 1 wherein said memorycomprises storage and upgrade means whereby said software drivers areretained for use in said modem means until replaced by the operation ofsaid communications software in response to a user instruction.
 25. Anintegrated computer and modem system for processing and transferringdata using a selected one of a plurality of telephone network accessdevices including at least one radiotelephone network access devicecomprising:computer means for processing data transferable over thetelephone network access device, and having a data communicationsprogram; modem means integrated with the computer means for transferringdata between said computer means and a remote data transfer device oversaid telephone network access devices, said modem means comprising:datapump means for transferring data between the modem means and thetelephone network access device; a data access arrangement operativelyconnected to said data pump means for providing a tip-and-ring interfacefor carrying signals between the modem means and said telephone networkaccess device at least when said telephone network access deviceoperates using a tip and ring interface; receive and transmit data linesoperatively connected to said data pump means to provide a receive lineand transmit line interface for carrying data between the modem meansand said telephone network access device at least when said telephonenetwork access device operates using a receive line and transmit lineinterface; control signal lines for carrying control signals forcontrolling and/or monitoring the operation of said radiotelephonenetwork access device; and jack means connected to said control signallines, said data lines, and said data access arrangement for providing adedicated external connection of said tip and ring interface, saidreceive line and transmit line interface, and said control signal linesas required to operably connect the modem means to said selectedtelephone network access device; wherein the data communications programof said computer comprises software drivers for selectively controllingthe operation of said modem means in conjunction with one of saidplurality of telephone network access devices, said data communicationsprogram operating to vary the operation of said control signal lines inresponse to said selected software drivers to permit the control of callplacement functions of different types of telephone network accessdevices by said modem means.
 26. A method of connecting a computingdevice to one of a plurality of types of telephone systems for transferof data, comprising the steps of:installing a modem in the computingdevice, the modem having a plurality of digital telephone control lineswith functions that vary under control of different software driverscorresponding to different types of digitally controlled telephonesystems, including a jack facilitating connection of the modem to eithera landline telephone system or a radiotelephone system, includingselective connection of said digital telephone control lines; providinga telephone terminal for the telephone system to be used; connectingbetween the modem jack structure and the telephone terminal a cableestablishing sufficient connections of said digital telephone controllines to the telephone terminal such that said computing device cancontrol data transfer connections made in said communications network;activating software in said computer to select an appropriate one ofsaid software drivers for the telephone system and cable being used, thesoftware operating to cause transmissions on said digital telephonecontrol lines to perform a data transfer connection control functionusing the connected telephone terminal.
 27. A portable computer systemfor transmitting data over one of at least two types of publiccommunications networks, each selectively accessible through anassociated communications network access device connectable to thesystem, comprising:computer means for generating and receiving acomputer data set to be transferred to a remote computing device overthe communications network access device; modem means connected to thecomputer means for interfacing said computer means to the communicationsnetwork access device for transfer of said computer data set;tip-and-ring interface means connected to the modem means and to anexternal connector of the portable computer system for transmitting andreceiving said computer data set in a standard landline tip and ringtelephone signal format; receive-and-transmit interface means connectedto the modem means and to an external connector of the portable computersystem for transferring said computer data set in digital form onseparate receive lines and transmit lines; and control means foractivating said tip and ring interface means at least when said data setis to be transferred using a standard landline telephone protocol andfor activating said receive-and-transmit interface means at least whensaid data set is to be transferred using a digitized transmission radiocommunications network.
 28. The portable computer system of claim 27,wherein said computer means is contained in a unitary housing and saidmodem means is installed within the housing.
 29. The portable computersystem of claim 28 wherein said tip-and-ring interface means and saidreceive-and-transmit interface means are connected to the same externalconnector of said portable computer system.
 30. The portable computersystem of claim 28 wherein said tip-and-ring interface means and saidreceive-and-transmit interface means are each connected to a differentexternal connector of said portable computer system.
 31. The portablecomputer system of claim 30 wherein said tip-and-ring interface meansand said receive-and-transmit interface means are each connected tostandard telephone connectors.
 32. The portable computer system of claim31 wherein said tip-and-ring interface means is connected to an RJ-11connector and said receive-and-transmit interface means are connected toan RJ-45 connector.
 33. The portable computer system of claim 27 furtherincluding digital telephone control means for generating communicationsnetwork access device control signals, said digital telephone controlmeans connected to an external connector of said portable computersystem.
 34. The portable computer system of claim 33 wherein saiddigital telephone control means includes a processing program fixed in anonvolatile digital data recording medium which causes the digitaltelephone control means to generate signals at said external connectorconnected to said digital telephone control means to control theoperation of at least one specific predetermined digitally controlledtelephone network access device when said device is connected to saidexternal connector through a cable having a predetermined configuration.35. A portable computer modem for transferring a data set between aportable computer and a remotely located computing device over one of atleast two types of public communications networks, each publiccommunications network selectively accessible through an associatedcommunications network access device connectable to the system,comprising:computer connecting means for making a data transferconnection of the modem to the portable computer; connector means forconnecting the modem to said associated communications network accessdevice and providing receive line and transmit line connections of themodem to said associated communications network access device;modulation means connected to the computer connecting means t:orselectively converting digital data signals, received from the portablecomputer and representing said data set, to analog signals, and forconvening analog data set signals received from said communicationsnetwork access device to digital data signals; receive-and-transmitinterface means connected to the modulation means and to said externalconnector means for transmitting and receiving said analog signals onsaid receive and transmit lines; digital interface control meansoperably connected to said computer connecting means and furtherconnected to said receive and transmit lines for selectivelytransferring digital data set signals in unmodulated form between saidportable computer and said remotely located computing device throughsaid communications network access device.
 36. A portable computer modemfor transferring data between a portable computer and one of at leasttwo types of public communications networks, each public communicationsnetwork selectively accessible through an associated communicationsnetwork access device connectable to the modem, comprising:computerconnecting means for making a data transfer connection of the modem tothe portable computer; external connector means for connecting the modemto said associated communications network access device and providingseparate receive line and transmit line connections of the modem to saidassociated communications network access device; modulation meansconnected to the computer connecting means for selectively conveningdigital data signals received from the portable computer to analogsignals, and for convening analog signals received from saidcommunications network access device to digital data signals;receive-and-transmit interface means connected to the modulation meansand to said external connector means for transmitting and receiving saidanalog signals on said separate receive lines and transmit lines;control means connected to said modulation means and said computerconnecting means for controlling the operation of the modulation meansthrough said receive-and-transmit interface means; and level controlmeans connected to said control means and said receive line forselectively driving said receive line with a DC voltage under thecontrol of said control means.
 37. The modem of claim 36 wherein saidlevel control means is connected to said transmit line and furtheroperates to drive said transmit line with a DC voltage level under thecontrol of said control means.
 38. A portable computer modem fortransferring a data set between a portable computer and a remotelylocated computing device through one of at least two types of publiccommunications networks, each public communications network selectivelyaccessible through an associated communications network access deviceconnectable to the modem, comprising:computer connecting means formaking a data transfer connection of the modem to the portable computer;external connector means external to a housing containing at least themodem for connecting the modem to said associated communications networkaccess device and providing separate receive line and transmit lineconnections of the modem to said associated communications networkaccess device; modulation means connected to the computer connectingmeans for selectively converting digital data signals representing thedata set and received from the portable computer to analog signals, andfor converting analog signals received from said communications networkaccess device to digital data signals representing a received data set;receive-and-transmit interface means connected to the modulation meansand to said external connector means for transmitting and receiving saidanalog signals representing the data set on said separate receive linesand transmit lines; control means connected to said modulation means andsaid computer connecting means for controlling the operation of themodulation means to transmit the data set through saidreceive-and-transmit interface means; and level sensing means connectedto said control means and said receive line for selectively sensing thevoltage level of said receive line under the control of said controlmeans.
 39. The modem of claim 38 wherein said level sensing means isconnected to said transmit line and further operates to selectivelysense the voltage level of said transmit line under the control of saidcontrol means.
 40. A portable computer modem for transferring a data setbetween a portable computer and a remotely located computing devicethrough one of at least two types of public communications networks,each public communications network selectively accessible through anassociated communications network access device connectable to themodem, comprising:computer connecting means for making a data transferconnection of the modem to the portable computer; external connectormeans external to a housing containing at least the modem for connectingthe modem to said associated communications network access devices andproviding separate receive line and transmit line connections andtip-and-ring connections of the modem to at least one said associatedcommunications network access device; modulation means connected to thecomputer connecting means for selectively converting digital datasignals representing the data set and received from the portablecomputer to analog signals, and for converting analog signals receivedfrom said communications network access device to digital data signals;receive-and-transmit interface means connected to the modulation meansand to said external connector means for transmitting and receiving saidanalog signals representing said data set on said separate receive linesand transmit lines; tip-and-ring interface means connected to themodulation means and to said external connector means for convening saidanalog data set signals to a standard landline tip and ring telephonesignal format for transmission and for convening received tip and ringtelephone signals to said analog signals.
 41. The modem of claim 40wherein said external connection means comprises a single externalconnector connected to said tip-and-ring interface means and saidreceive-and-transmit interface means.
 42. The modem of claim 40 whereinsaid external connection means comprises two external connectors, afirst connector connected to said tip-and-ting interface means and asecond connector connected to said receive-and-transmit interface means.43. The modem of claim 42 wherein said first and second connectors arestandard telephone connectors.
 44. The modem of claim 43 wherein saidfirst connector is an RJ-11 connector and said second connector is anRJ-45 connector.
 45. The modem of claim 40 further including digitaltelephone control means for generating communications network accessdevice control signals, said digital telephone control means connectedto said external connector means of said modem.
 46. The modem of claim45 wherein said digital telephone control means includes a processingprogram fixed in a nonvolatile digital data recording medium whichcauses the digital telephone control means to generate signals at saidexternal connector means connected to said digital telephone controlmeans to control the operation of at least one specific predetermineddigitally controlled telephone network access device when said device isconnected to said external connector through a cable having apredetermined configuration.
 47. The modem of claim 46 wherein saiddigitally controlled telephone network access device is a cellularradiotelephone.
 48. A portable computer system adapted for transferringdata over a radio communications network when directly connected to aspecific radio network access device having a specific externalconnector for allowing external control of the radio network accessdevice, comprising:a transportable computer housing; computer meansmounted within said computer housing for processing data transferrableover a radio network access device; modem means operably connected tothe computer means and mounted substantially within said transportablecomputer housing for transferring data between said computer means and aremote data transfer device over a radio network access device, saidmodem means comprising, data pump means for transferring data betweenthe modem means and a radio network access device; receive and transmitdata lines operatively connected to said data pump means to provide areceive and transmit line interface for carrying data between the modemmeans and a radio network access device; control signal linesprogrammable to carry control signals for controlling and/or monitoringthe operation of different types of radio network access devices; andprogram controllable modem controller means connected to said computermeans, said control signal lines, and said data pump means forcontrolling the operation of said modem means in response to a modemcontrol program to permit the control of a call placement function of aspecific type of radio network access device by said modem: jack meansmounted on said transportable computer housing and connected to saidcontrol lines and said receive and transmit data lines, for providing anexternal connection of said receive and transmit line interface toconnect said modem means with a plurality of types of radio networkaccess devices; matched program and cable means corresponding to aspecific radio network access device for connecting and controlling thecomputer system to transfer data over a radio communications networkupon connection with said specific radio network access device, saidmatched program and cable means includinga device specific multi-linecable means for interconnecting at one end with said jack means andconnectable at the other end with a device specific external connectionof said specific radio network access device to interconnect saidreceive and transmit data lines and said control lines with saidspecific external connector of the radio network access device; andprogram means for programming said modem controller means to cause saidcontrol lines to function in a manner suitable only for the specificradio network access device with which said cable means is adapted to beconnected.
 49. A kit for programming and connecting a computerconnected, programmable modem to one of a plurality of different typesof cellular telephones having different control protocols, respectively,for controlling phone functions and having different external electricalconnectors, respectively, to receive external control signals formattedin accordance with the control protocols for controlling cellular phoneoperation to allow data to be transferred and received by the computerover a cellular network, comprisinga cellular telephone cable means forinterconnecting a specific one of the cellular telephones to the modem,said cellular telephone cable means including a conductive cable havinga modem connector at one end for connection with the modem and acellular telephone connector at the other end for connection with thespecific external electrical connector of one of the plurality ofcellular telephones, and a non-volatile digital data recording mediumcontaining a software driver adapted to be loaded into the programmablemodem for causing the modem to produce control signals in accordancewith a control protocol of said specific cellular telephone using saidconductive cable.
 50. A method of upgrading a programmable interfacedevice which drives a radio network interface device for transfer of adata set between the programmable interface device and a remotelylocated computing device over a radio network, so that the programmableinterface device will drive a specific new radio network interfacedevice, comprising the steps of:providing a programmable interfacedevice with a memory for storing one or more software drivers and acommon connection means for transferring data signals between theprogrammable universal interface device and said radio communicationsnetwork interface devices; providing a driver kit including a cable forconnecting the common connection means to at least one specific radiocommunications network interface device through one or more lineconnections and a software driver containing information for controllingthe operation of the specific radio communications network interfacedevice, said software driver information including information assigningparticular control signal transmissions to particular said one or moreline connections established by the cable; installing the cable from thedriver kit between the programmable interface device and the radiocommunications network interface device to establish at least one datatransmission line connection between the programmable interface deviceand the radio communications network interface device; installing thesoftware driver from the software driver kit in a storage memory of theprogrammable interface device; activating the programmable interfacedevice to select said software driver to control operation of saidspecific radio communications network interface device by generatingcontrol signal transmissions and selectively routing said signals toline connections established by the cable to control said radiocommunications network interface device for establishing data transferconnections in said radio communications network to define the identityof the remotely located computing device.
 51. The method of claim 50wherein the programmable interface device comprises a portable computingdevice.
 52. The method of claim 51 wherein the common connection meanscomprises an external jack on the portable computing device.
 53. Themethod of claim 52 wherein the external jack comprises a serial digitaldata port.
 54. The method of claim 51 wherein the programmable interfacedevice comprises a data modem.
 55. The method of claim 54 wherein thedata modem comprises a microprocessor connected to control a pluralityof data transfer interfaces operable with different and furtherconnected to control a plurality of programmable control lines connectedto said network interface device by said cable.
 56. The method of claim50 wherein the programmable interface device comprises a microprocessorconnected to control a plurality of data transfer interfaces havingdifferent configurations and operable with different radiocommunications networks.
 57. The method of claim 56 wherein themicroprocessor further controls a plurality of programmable controllines connected to said radio communications network interface device bysaid cable.
 58. The method of claim 56 wherein said data transferinterfaces include at least an analog modulated RX-TX interface and adigital RX-TX interface.
 59. The method of claim 50 wherein theprogrammable interface device comprises a microprocessor that formatsthe data set for transmission.
 60. The method of claim 59 wherein themicroprocessor formats the data set into data blocks for transmission.61. A system for transferring data between a computing device and aremote device using a selected one of a plurality of communicationsnetwork access devices including at least one radio communicationsnetwork access device, comprising:a data transmission and formattingcircuit connected to said computing device and further connectable by atleast one of a receive line and transmit line interface and a tip andring line interface to one of said communications network access devicesfor transferring data between said computing device and a remote datatransfer device over said connected communications network accessdevice, said data transmission and formatting circuit operatingselectively to transfer digital data between the computing device andthe remote data transfer device in one of at least two modes dependingon the type of communications network access device in use: a first modeusing said receive line and transmit line interface to transfer a signalrepresenting digital data, and a second mode using said tip and ringinterface to transfer an analog signal representing digital data, saiddata transmission and formatting circuit comprising:controller meansconnected to said computer means for controlling the mode of operationof said data transmission and formatting circuit and for controllingdestination addressing functions of said connected communicationsnetwork access devices in response to a software driver; and memorymeans connected to said controller means for storing one or more of saidsoftware drivers, each including data specific to at least oneparticular communications network access device for use by saidcontroller means in selecting an appropriate one of said modes ofoperation of the data transmission and formatting circuit and generatingappropriate destination addressing control commands specific to saidparticular communications network access device for establishingtransmission between said computing device and said remote data transferdevice; and a data communications program operating in the computingdevice for accessing one of a plurality of said software drivers andthereafter selectively downloading one or more of said software driversto said memory means for subsequent use in transferring data using anassociated communications network access device connected to said datatransmission and formatting circuit.
 62. A kit for upgrading aprogrammable interface device which drives a radio network interfacedevice for transfer of a data set between the programmable interfacedevice and a remotely located computing device over a radio network, sothat the programmable interface device will drive a specific new radionetwork interface device, comprising:providing a programmable interfacedevice with a memory for storing one or more software drivers and acommon connection means for transferring data signals between theprogrammable universal interface device and said radio communicationsnetwork interface devices; a cable connecting a common connection meansof the programmable interface device which transfers data signalsbetween the programmable interface device and said radio communicationsnetwork interface device to at least one specific radio communicationsnetwork interface device through one or more line connections; and asoftware driver containing information for controlling the operation ofthe specific radio communications network interface device, saidsoftware driver information including instructions for generatingcontrol signal transmissions for establishing data transfer connectionsin said radio communications network to define the identity of theremotely located computing device, and further including instructionsfor selectively routing particular control signal transmissions toparticular line connections established by the cable, said softwaredriver installable in a storage memory of the programmable interfacedevice.
 63. The kit of claim 62 wherein the programmable interfacedevice comprises a data modem and the software driver comprisesprogramming information loaded into a storage memory of the data modemto control the operation of the data modern.
 64. A portable computermodem system for transferring a data set between a portable computer anda remotely located computing device through one of at least two types ofradio communications networks, each radio communications networkselectively accessible through an associated radio network access deviceconnectable to the modem, comprising:computer connecting means formaking a data transfer connection of the modem to the portable computer;external connector means external to a housing containing at least themodem for connecting the modem to said associated radio network accessdevice and providing separate receive line and transmit line connectionsof the modem to said associated radio network access device: modulationmeans connected to the computer connecting means for selectivelyconverting digital data signals representing the data set and obtainedfrom the portable computer to analog signals, and selectively conveninganalog signals received from said radio network access device to digitaldata signals representing a received data set; receive-and-transmitinterface means connected to the modulation means and to said externalconnector means for transmitting and receiving signals representing thedata set on said separate receive lines and transmit lines; and controlmeans connected to said modulation means and said receive and transmitinterface means for selectively controlling the modulation means and thereceive and transmit interface means to transfer the data set betweenthe computing device and the remote data transfer device in one of atleast two modes, the selected mode depending on the type of radionetwork access device in use: a first mode in which said control meansdigitally formats said data set according to a transmission protocol anddigitally transmits the formatted data set to the radio network accessdevice over the receive and transmit interface, and a second mode inwhich said control means digitally formats said data set according to atransmission protocol, and activates said modulation means to modulatesaid formatted data set and transmit a modulated formatted analog datasignal representing the formatted data set to the receive and transmitinterface and thus to the radio network access device and the remotecomputing device.
 65. The modem system of claim 64 wherein the same saidreceive lines and transmit lines are used in both said first and secondoperating modes.
 66. The modem system of claim 64 wherein thetransmission protocol in the second mode comprises separating the dataset into packets and adding error detection formatting to the packets.